Chemistry analyzers have been developed to automatically determine the chemical composition of a given sample. Such analyzers are also known as clinical analyzers. In the health care industry, chemistry analyzers are frequently used to analyze fluid or tissue specimens from a patient to determine whether the patient may be suffering from a disease, illness, or deficiency. A variety of tests may be performed on a particular sample, using techniques such as spectrophotometry and immunochemistry, to determine both the presence and concentration of a particular substance, in that sample. For example, various types of chromatography, spectrometry, electrophoresis, and immunochemical tests may be performed on the sample. Often, in the health care industry, such tests on blood or urine are conducted, to determine the concentrations of the various chemical constituents (i.e., analytes). For example, tests may be conducted to determine the concentrations of potassium, sodium, protein, glucose, and calcium.
Currently, automatic chemical analyzers have the capability of flagging any abnormal data taken from a tested sample with respect to a given chemical. An abnormal result may arise, either because the patient has an abnormality that reflects as a change in the activity or concentration of a particular analyte, or as a result of an error. The possible causes for the error are several and include pre-analytical errors, such as samples being collected into incorrect tubes or samples being handled incorrectly before despatch to the laboratory, or analytical errors due to incorrect machine operation, such as a bubble or clot in a flow line of the machine for example. These types of abnormal results are referred to herein as “artifactual” or “aberrant” results, and differ from abnormal results which are real and due to a physiological problem in the patient.
Abnormal results are typically flagged and reviewed before being released. One of the typical review procedures is to ascertain that the instrument is operating properly by running a quality control check on the machine. Another possible review procedure is to repeat the test, to determine if the result occurs again on the sample. However, in spite of the test being repeated and the machine passing a quality control test, the abnormal result may still remain. The technologist must decide whether the abnormal result represents a physiological abnormality in the patient, or whether the result is abnormal as a result of an artifact in the collection, handling, or analysis of the sample. The potential consequence of releasing an artifactual result as a real, physiological result, may include misdiagnosis and mistreatment, potentially resulting in harm to the patient and liability to the treating organization.
Accordingly, additional assistance in differentiating physiological from artifactual results is desired. Furthermore, it is desirable if such assistance can include the automatic identification of artifactual results, and the automatic indication of the possible causes of the artifactual result which has been identified.